December moving forward...pattern disco

[Logan11]

Well Post 12/15 we are deeper into the cold season and maybe even if we do revert to a form of the old pattern we would be far enough north for some gradient events. Whereas in later November that was clearly a hopeless situation.. But - hey NH and ME did score a snowstorm amiodst that.

There has been some signs for a while now. We again walk the gradient line near mid month, but it's too early to say if the potential warm up is like any old passing warm up that we always get...or if it last for a while. The flow gets more zonal, but gradient like at the same time...so expect maybe alternating periods perhaps, but we continue to see swings in daily details with the 6-10 day having a tough enough time to nail down...nevermind the 11-15 day. It still doesn't look all that appealing come mid month. The ridge may try to build back a bit shortly after?

[CT Rain]

You were pretty positive about that storm IIRC. Everyone was focused on Thursday night's coating and by Wednesday you started banging the drum that the weekend storm was looking good.

Voice of reason in sea of irrationality.

Anyway sorry to be a downer about the pattern... I'd like a storm... or something. This has just been dreadfully boring.

[Tropopause_Fold]

CPC just updated after the EURO ENS stomped our dreams and dashed our hopes. Every day they extend the torch further west....

i'm actually kind of surprised by that. i don't know that i'd paint high probs like that for AN in that 10-16 timeframe. i mean i could see it ending up above normal in that period, but imo, it's a lower probability than what they have for that stretch.

i'm pretty comfortable calling it normal to slightly above for that period. not that it matters.

[CoastalWx]

Voice of reason in sea of irrationality.

Anyway sorry to be a downer about the pattern... I'd like a storm... or something. This has just been dreadfully boring.

Yeah the mid month period could be a downer. Would be funny if that colder air later next week was accompanied by just sun.

I'm hoping the period just before day10 could fire something up, but I don't have confidence in that. We'll know in the next couple of days, but I hope that trough isn't too positively tilted. The past couple of days it was really far west, now it has shifted east. Might be because of that ridge getting flattened out in the GOA, causing faster flow into Canada and "scooting" this along.

Pretty sure the 1st half of the month is warmer than normal..and possibly the whole month. Certainly nothing exciting on the horizon, but this has been said too many times...lol.

[CoastalWx]

Looks like the wording is getting bunched up with this new skin.

[dryslot]

This thread kind of reminds me when i was younger and all we had were vinyl lp's to play on our tuntables and the album had a scratch in it and it would just keep playing in the same spot over and over and over again

[weathafella]

No disrespect but you have been flopping around the last few days..Just this morning you posted how the oattern change is well underway and should be complete by 12/25..Now it's maybe the Euro ens are right and the 15-30th is 10-15 above normal

Show me a post where I didn't acknowledge the.mid month torch? That's why the pattern change takes 15 days imho. And you don't want me to multiquote your mood swings.....

[Ginx snewx]

This thread kind of reminds me when i was younger and all we had  were vinyl lp's to play on our tuntables and the album had a scratch in it and it would just keep playing in the same spot over and over and over again

Nah 8 tracks that play the same over and over again. Think that is how come I know every word to all Stones ,Zep, Aerosmith songs from the 70's. Fall asleep with headphones on with the 8 track player.

[CoastalWx]

Pattern overall, stinks. Repeat that.

[dryslot]

Nah 8 tracks that play the same over and over again. Think that is how come I know every word to all Stones ,Zep, Aerosmith songs from the 70's. Fall asleep with headphones on with the 8 track player.

Had one of those as well along with the FM converter in the car because all we had was an am radio, Mine use to eat 8 tracks like it was its job, Christmas ribbon for all.......

[weathafella]

Pattern overall, stinks. Repeat that.

8 days...8 days left in the period.

8 more days.. days left in the period.

[toronto blizzard]

Do the euro ensembles still show a gradient pattern in the long range?

[CoastalWx]

Do the euro ensembles still show a gradient pattern in the long range?

Yeah but it's along the northern tier of the US..a little too close for comfort. Hopefully the ensembles are right in hinting that the +EPO relaxes once again near the end of the run.

[Clinch Leatherwood]

8 days...8 days left in the period.

8 more days.. days left in the period.

I'm getting really hungry.

[HM]

Rick....I think the Euro ensembles....a mean of 51 members should be given weight. The mid.month torch is a signal thats growing. HM has a great bead on it from many days ago.

Thanks... Of all the things that are happening from late November into December, that was one of the strongest signals showing up. Mid-December would see an anomalous warming possibly and the temperature distribution would look quite strange across the CONUS for a while. In October, I thought the -NAO response we would get in mid-Nov would lead to the cold air across the SE plus I thought that the general La Nina/-PDO wavelengths would focus the cold in the SE USA. Obviously the warmth across the North overwhelmed (we did get a +h5 anomaly in the North Atlantic mid-Nov, see below, but that had no chance against the developing Alaskan Vortex and strong stratospheric vortex).

Finally, we are seeing the early winter La Nina wavelengths allowing for some cold air to enter the CONUS. This lingering regime is what I thought would make the CONUS look kind of kooky for a La Nina Dec...at least for a while. So while the South sees negatives because of the cold shots, the north could go well above normal with the evolving mid-Dec pattern. We'll see...

[CoastalWx]

Thanks... Of all the things that are happening from late November into December, that was one of the strongest signals showing up. Mid-December would see an anomalous warming possibly and the temperature distribution would look quite strange across the CONUS for a while. In October, I thought the -NAO response we would get in mid-Nov would lead to the cold air across the SE plus I thought that the general La Nina/-PDO wavelengths would focus the cold in the SE USA. Obviously the warmth across the North overwhelmed (we did get a +h5 anomaly in the North Atlantic mid-Nov, see below, but that had no chance against the developing Alaskan Vortex and strong stratospheric vortex).

Finally, we are seeing the early winter La Nina wavelengths allowing for some cold air to enter the CONUS. This lingering regime is what I thought would make the CONUS look kind of kooky for a La Nina Dec...at least for a while. So while the South sees negatives because of the cold shots, the north could go well above normal with the evolving mid-Dec pattern. We'll see...

This pattern has looked kooky for a while now...I think we mentioned that a couple of weeks ago. Weak cool anomalies hanging around down south...helped out by that cut off, while the AK vortex has raged on with a fast pac jet recently. Very -PDO like for Novie. I do remember you bringing up the kooky pattern.

[CoastalWx]

Although my guess is that mid December will have warm anomalies in a lot of places..not just the nrn tier.

[HM]

This pattern has looked kooky for a while now...I think we mentioned that a couple of weeks ago. Weak cool anomalies hanging around down south...helped out by that cut off, while the AK vortex has raged on with a fast pac jet recently. Very -PDO like for Novie. I do remember you bringing up the kooky pattern.

I just wished I had timed the MJO / wind anomaly progression as good as I did in October. Looking back on it (I know, I know; hindsight is 20/20), the quick MJO response then was pretty obvious. This go-around, it seems that everything favors the opposite moving forward. ENSO-dominate forcing is likely through most of December with a possible flareup in the IO late dec/early Jan.

If we can continue to pop a NE PAC ridge, this would support the coldest air across the upper Midwest / New England in early January as wavelengths elongate. I don't think the dreaded mid-dec warm potential will be long-lasting.

[Typhoon Tip]

Thanks... Of all the things that are happening from late November into December, that was one of the strongest signals showing up. Mid-December would see an anomalous warming possibly and the temperature distribution would look quite strange across the CONUS for a while. In October, I thought the -NAO response we would get in mid-Nov would lead to the cold air across the SE plus I thought that the general La Nina/-PDO wavelengths would focus the cold in the SE USA. Obviously the warmth across the North overwhelmed (we did get a +h5 anomaly in the North Atlantic mid-Nov, see below, but that had no chance against the developing Alaskan Vortex and strong stratospheric vortex).

Finally, we are seeing the early winter La Nina wavelengths allowing for some cold air to enter the CONUS. This lingering regime is what I thought would make the CONUS look kind of kooky for a La Nina Dec...at least for a while. So while the South sees negatives because of the cold shots, the north could go well above normal with the evolving mid-Dec pattern. We'll see...

I'm going the other way with this analysis. I think there are some early precursors evident for a callapse in the AO and the 3 night consistency in the GFS cluster for falling values - despite their ills with initialization - is going to turn out telling. Something also that folks should remember is that the AO does not have to correct all the way negative. A 3SD downward mode shift signals quite alot, and since the cryospheric recovery has proven robust over normal this season, I think it gets dicey real quick to assume that won't play a role in distribution of temperature anomalies.

I'm sensing that the GFS cluster is largely ignored in lieu of the Euro. My experience/usage with the GFS mean is productive enough. So indeed. -we'll see.

[CT Rain]

I just wished I had timed the MJO / wind anomaly progression as good as I did in October. Looking back on it (I know, I know; hindsight is 20/20), the quick MJO response then was pretty obvious. This go-around, it seems that everything favors the opposite moving forward. ENSO-dominate forcing is likely through most of December with a possible flareup in the IO late dec/early Jan.

If we can continue to pop a NE PAC ridge, this would support the coldest air across the upper Midwest / New England in early January as wavelengths elongate. I don't think the dreaded mid-dec warm potential will be long-lasting.

It seems like this MJO wave is going to have trouble advancing through the Pacific though. Between unfavorable MJO phases and an ice cold stratrosphere with little blocking I'm not sure how to get much long lasting cold in here.

[weatherwiz]

Although my guess is that mid December will have warm anomalies in a lot of places..not just the nrn tier.

With the PNA being so negative it was a bit odd to see such cool anomalies across the SE but that cut-off really did it's job.

[HM]

I'm going the other way with this analysis. I think there are some early precursors evident for a callapse in the AO and the 3 night consistency in the GFS cluster for falling values - despite their ills with initialization - is going to turn out telling. Something also that folks should remember is that the AO does not have to correct all the way negative. A 3SD downward mode shift signals quite alot, and since the cryospheric recovery has proven robust over normal this season, I think it gets dicey real quick to assume that won't play a role in distribution of temperature anomalies.

I'm sensing that the GFS cluster is largely ignored in lieu of the Euro. My experience/usage with the GFS mean is productive enough. So indeed. -we'll see.

See above. I expect the warmth to be brief. In fact, a while ago, I gave New England a threat on Dec 20-23 this year. The cryosphere is definitely impressive but so is the polar vortex.

[Damage In Tolland]

See above. I expect the warmth to be brief. In fact, a while ago, I gave New England a threat on Dec 20-23 this year. The cryosphere is definitely impressive but so is the polar vortex.

The exact time many are calling for a nasty torch. My house money is on Rutgers and HM

[CoastalWx]

I just wished I had timed the MJO / wind anomaly progression as good as I did in October. Looking back on it (I know, I know; hindsight is 20/20), the quick MJO response then was pretty obvious. This go-around, it seems that everything favors the opposite moving forward. ENSO-dominate forcing is likely through most of December with a possible flareup in the IO late dec/early Jan.

If we can continue to pop a NE PAC ridge, this would support the coldest air across the upper Midwest / New England in early January as wavelengths elongate. I don't think the dreaded mid-dec warm potential will be long-lasting.

Well I get the sense the flow across the north will be fast paced if the flow becomes more zonal. At least if you believe the ridge breaking down for a time which I do.

While anything can go on the last frames of ensembles...they did try to build the ridging back up again, so hopefully that continues into the third week of the month. Going to be interesting since tropical forcing may be at a minimum in about 2 weeks.

[Typhoon Tip]

See above. I expect the warmth to be brief. In fact, a while ago, I gave New England a threat on Dec 20-23 this year. The cryosphere is definitely impressive but so is the polar vortex.

I know. It is...however, we've bled out cold to the 50th parallel more so than your latter point would suggest - that's the tick.

[weatherwiz]

The spread in the ensembles with how the NAO/AO/EPO will act through the next few weeks is pretty crazy. You would either think some sort of pattern change could really try and occur around mid-month or just before Christmas and at this time there could certainly be potential for a big storm system. Just b/c we may remain well above-average doesn't mean we can't get one lucky period where everything unfolds to give us a winter event...like what happened end of October.

[HM]

The exact time many are calling for a nasty torch. My house money is on Rutgers and HM

There is definitely a mixed event / ice threat potential beforehand. A lot of low level cold air will be around after the 12th as heights rise.

[HM]

Well I get the sense the flow across the north will be fast paced if the flow becomes more zonal. At least if you believe the ridge breaking down for a time which I do.

While anything can go on the last frames of ensembles...they did try to build the ridging back up again, so hopefully that continues into the third week of the month. Going to be interesting since tropical forcing may be at a minimum in about 2 weeks.

The "torch" could end up being more N-C US than New England, given the amount of cold air that will exist in eastern Canada. Yes, the NAO will be positive but I agree with tip that the amount of cold air needs to be considered.

An annoying December for sure, especially for New England. At least in the Mid-Atlantic, we know we are screwed outside of CAD areas.

[Damage In Tolland]

There is definitely a mixed event / ice threat potential beforehand. A lot of low level cold air will be around after the 12th as heights rise.

Yeah seems like late next week or weekend would be the timeframe for that..then hopefully the warmup is brief before the 20-23rd threat. Dec still comes in above normal but don;t think these calls of of +3 to +5 will verify

[Snowstorms]

The "torch" could end up being more N-C US than New England, given the amount of cold air that will exist in eastern Canada. Yes, the NAO will be positive but I agree with tip that the amount of cold air needs to be considered.

An annoying December for sure, especially for New England. At least in the Mid-Atlantic, we know we are screwed outside of CAD areas.

Seems as though my region may escape the worst though with the temperature gradient so strong, precipitation can fall as either and I fear that for most of December across a large part of the East. Jet stream pattern is too zonal for anything big with a weak STJ.

The pattern resembles Dec 07, other than the big AK vortex and slightly different Pacific pattern.

I'm thinking off a drop off in terms of the AO come late Dec-early Jan though with the stratosphere as cold as it is, I dont see any huge blocking this year compared to the past two.

Whats your thought on the extremely low AP Index, and AO?